You must be thinking about the difference between these two ways of accountlive.com/password/reset. Well, both the methods lead to the same destination; however, the way of resetting the password is different in these two. You can choose the first one if the Microsoft account has the two-step authentication feature is on.
On the other hand, account.live.com/acsr needs to be visited if the feature is disabled. To reset Account Live password, use either your registered email address or phone number at https://account.live.com/password/reset, or an alternate email address at account.com/acsr.
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